Closing the security gap is important, but so too is support for calls over mobile broadband networks in the U.S. Last year, Skype partnered exclusively with Verizon Wireless as the only carrier to allow 3G Skype calls, thus limiting Skype usage on other networks here. Hacks and workarounds could be used to enable 3G Skype calls on other carrier networks, but those are no longer needed due to the most recent software update.

Adding support for Skype calls could be the final puzzle piece in my mobile communications plan. I often carry the Samsung Galaxy Tab, a 7-inch Android tablet, with me everywhere. The device can do everything my smartphone does: run the same apps, use location-based services with GPS, surf the web and more. But the one key item it can’t do, and the main reason I still take a smartphone along with me, is easily handle voice calls. The functionality is there in terms of hardware, but it’s blocked by Samsung, likely at the request of the U.S carriers. In some other countries, Galaxy Tab owners can and do use the tablet for cellular voice calls.

With the latest Skype update and support for 3G calling, however, I may be able to get away with only carrying my tablet. I’ve successfully tested Google Voice forwarding to my SkypeIn number, so with a single phone number, voice calls could be routed to my tablet while on a 3G network. Does this set up the potential for a potential Skype-branded handset in the future? If the company can work another carrier deal — this time a data-only plan with no voice requirement — Skype could potentially power mobile conversations over Wi-Fi, 3G, 4G and beyond.

I’ve already tested the new update on my Tab and had a voice call over T-Mobile’s 3G network with my son this morning. The call sounded like any other voice call on a cellular network, but used only the data portion of T-Mobile’s network. Using Skype’s newest software, my smartphone just might have gained a 7-inch display, although I’ll have to test this solution over a longer term.